Cornyebacterium and Rhodococcus Flashcards
What shape is Corynebacterium?
club shaped
How does Corynebacterium appear on gram stain?
gram positive rods
What are palisades?
the tendency for bacteria to form in clumps or parallel groups
What size colonies does Corynebacterium have?
small to medium, non-hemolytic colonies
What bacteria does Corynebacterium share cell wall antigens with?
Mycobacterium, Rhodococcus, and Nocardia
What dpes the human pathogen of Corynebacterium diptheriae cause?
diptheria
What countries still have a diptheria problem?
under developed countries
What clinical signs are associated with diptheria?
conjunctivits, bull neck, severe myocarditis
What does Corynebacterium renale cause in cattle?
pyelonephritis
What does Corynebacterium renale cause in sheep and goats?
posthitis
What is the morphology of Corynebacterium renale?
short, stumpy rods which may be thicker on one end - non hemolytic
What does Corynebacterium renale grow well on?
BAP and sterile urine
Is Corynebacterium renale catalase positive or negative?
positve
What test is pretty indicitive that Corynebacterium renale is the pathogen in question?
urease - rapid urease result
What is the natural habitat of Corynebacterium renale?
urethra and prepuce of normal cattle, sheep, and goats
What type of infection is Corynebacteria renale?
ascneding usually in periparturient cows
Is immunity from Corynebacteria renale possible?
nope
What is used to treat Corynebacteria renale?
penicillin
What specific urinary lesion does Corynebacteria renale cause?
pizzle rot - ulcerative posthitis
What causes pizzle rot?
excessive protein in the diet leads to increased quantities of urea in the urine. C. renale breaks down the urea and converts it into ammonia which is very irritating to the skin and mucosa around and in the prepuse
How do you treat pizzle rot?
topical ointments or surgical intervention
What are the two biovars of Corynebacterium pseudotuberculosis?
biovar ovis and biovar equi
How does biovar ovis react with nitrate, what does it cause, and in what species?
it is nitrate negative and causes caseous lymphadenitis in sheep and goats
How does biovar equi react with nitrate, what does it cause, and in what species?
it is nitrate positive and causes abscesses in horses
Which biovar of Corynebacterium pseudotuberculosis infects cattle?
both of them
How does Corynebacterium pseudotuberculosis appear on gram stain?
gram positive pleomorphic short rod that can be mistaken for cocci
What do the colonies of Corynebacterium pseudotuberculosis look like?
small grayish to yellow and sometimes pinkish colonies which can fragment easily - hemolytic pattern varies
What definitive tests are used to identify Corynebacterium pseudotuberculosis?
urease and CAMP
How does Corynebacterium pseudotuberculosis react on CAMP?
it has a reverse CAMP reaction and inhibits staphylococcal beta hemolysin
What toxins does Corynebacterium pseudotuberculosis have?
phospholipase D and surface lipid
What is the basis for the vaccine for Corynebacterium pseudotuberculosis?
phospholipase D
What is the surface lipid of Corynebacterium pseudotuberculosis toxic to?
phagocytes
Where is Corynebacterium pseudotuberculosis present?
in soil, in abscesses, and on skin
How is Corynebacterium pseudotuberculosis spread?
when an abscess ruptures the organism contaminates feeders, waterers, etc.
How does Corynebacterium pseudotuberculosis infect?
through wounds, abrasions, insect bits, shearing wounds, and it can be inhaled
Where does Corynebacterium pseudotuberculosis travel after entering a host?
it travels to draining lymph nodes
What type of parasite is Corynebacterium pseudotuberculosis?
facultative intracellular parasite
What type of lesions does Corynebacterium pseudotuberculosis cause?
onion-skin lesions
What species does Corynebacterium pseudotuberculosis commonly infect?
sheep and goats
What region is biovar equi seen in?
The west - specifically California and Colorado
What lesion does biovar equi cause (specific disease)?
pigeon fever or Dryland distemper
Aside from goats, sheep, and horses, what species does Corynebacterium pseudotuberculosisinfect?
cattle, bison, camels, and humans
How is Corynebacterium pseudotuberculosis diagnosed?
based on clinical signs or the synergistic hemolysis inhibition test
What aids in preventing against Corynebacterium pseudotuberculosis infection?
antigen against the phospholipase - once abscesses form the antibody is not helpful
How can C. pseudotuberculosis be prevented?
quarantine, drain abscesses, and immunization
How can C. pseudotuberculosis be treated?
drain the abscesses or injecting them with Draxxin
What is the morphology of Rhodococcus equi?
large rod (in liquid media) with pleomorphism ranging into cocci (on plate media)
What do the colonies of Rhodococcus equi look like?
non hemolytic small to large, distinct, moist, mucoid, and flowing
How does Rhodococcus equi react in carbohydrates?
it doesn’t ferment
What other test helps to identify Rhodococcus equi?
CAMP - strong reaction
What antigens are specific to Rhodococcus equi?
virulence-associated protein A and mycolic-type acids
What is the natural habitat of Rhodococcus equi?
intestinal tract of horses especially in young foals and grows in soil
What is Rhodococcus equi resistant to?
pretty much everything - it is very hardy
What diseases does Rhodococcus equi cause?
suppurative bronchopneumonia, enteritis, internal abscesses, and joint infections
Aside from equine, what does Rhodococcus equi infect?
swine and humans
In swine. what is Rhodococcus equi maybe secondary to?
tuberculosis
What is immunity to Rhodococcus equi dependent on?
age - presence of macrophages
Is there a vaccine for Rhodococcus equi?
no
How do you treat a Rhodococcus equi?
long-acting macrolides and rifampin
